Phileas - You must have joined eBay early in the piece, before they tightened up the financial requirements. eBay hates losing money, and they didn't take long to ensure they got paid, when a seller didn't pay on time.
I used to be a store owner on eBay, but they got too hungry, and they didn't want "hobby" sellers, only the "biggies" with massive turnover.
It suits me fine, I rarely go there now, because there's plenty of alternatives - mostly in the sellers own websites - and I have no need to deal with their rapaciousness.
Everything on eBay is slanted in eBays favour, there's no fairness, no adjudication, no longer any ability to leave negative feedback for scumbag buyers, and no longer any good feeling when dealing with them.